Article forming apparatus



June 1942' J. s. STULL "ARTICLE FORMING APPARATUS Filed Dec. 24, 1940 2 Sheets-Sheet 1 Jun 9, 1942. J. 5. STULL A A 83 ARTICLE FORMING APPARATUS Filed Dec. 24, 1940 2- Sheets-Sheet 2 I h ll" 27 as- 27 Afro/awn Patented June 9, 1942 ARTECLE FORMING APPARATUS John S. Stull, Chicago, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 24, 1940, Serial No. 371,572

Claims.

This invention relates to article forming apparatus and more particularly to article forming apparatus for automatic machines designed to produce piece parts.

An object of this invention is to provide an improved apparatus for rapidly and accurately forming the peripheral surface of an article.

In accordance with the general features of this invention there is provided in one embodiment thereof, as applied to the tool slide of an automatic screw machine, an apparatus for peripherally knurling the work or article carried by the rotating spindle of the machine. Specifically, the improved apparatus comprises a standard, carried by the slide, in which are secured three equally spaced parallel sleeves, each having a cam groove, the sleeves each having reciprocably and rotatably carried therein a knurling roll holder or shaft carrying a radial pin which is engaged in the cam groove. Mounted eccentrically and freely rotatable upon the forward ends of the shafts are aligned knurling rolls arranged for simultaneous engagement with the periphery of the rotating article to be knurled. Means including resilient means is operatively associated with the shafts and the standard whereby the shafts are held in an advanced position relative to the standard and the slide when the latter is in its retracted position, the shafts advancing with the standard in the operation of the apparatus as a unit for a predetermined distance until adjustable stop means connected to the rear ends of the shafts engages an abutment, preventing further advance thereof. In the operation of the screw machine the slide carries the standard forward together with the shafts supporting the knurling rolls to predeterminedly position the knurling rolls longitudinally of the article, as determined by the stop means. In timed relation to such positioning of the rolls and in the continued movement of the slide the cam grooves are effective to simultaneously rotate the shafts, by means of the attached pins engaged in the cam grooves, thus moving the eccentrically mounted knurling rolls into operative engagement with the rotating article. The arrangement is such that the knurling rolls are moved through a relatively long arcuate path with respect to the article to be knurled and engage the article near dead center, thus producing the required leverage to provide a heavy pressure to form the knurl. During this operative movement of the knurling rolls the resilient means are compressed and when the slide is retracted with the apparatus the resilient means act to retract the rolls from the knurled article and return the associated shafts to their normal position relative to the standard.

Other objects and advantages of this invention will more fully appear from the following detailed description, taken in conjunction with the accompanying drawings, in which Fig. 1 is a central vertical sectional view, partly in elevation, illustrating the invention as embodied in a knurling apparatus applied to an automatic screw machine, which is shown frag mentarily;

Fig. 2 is an enlarged vertical section, partly in elevation, taken on the line 2--2 of Fig. 1;

Fig. 3 is an enlarged vertical section taken on the line 33 of Fig. 1, and

Fig. 4 is an enlarged fragmentary plan section taken on the line 44 of Fig. 1.

Referring to the drawings, particularly to Figs. 1 and 2, wherein the knurling apparatus embodying the features of this invention is shown applied to an automatic screw machine of the type in which a plurality of tools (not shown) are positioned at spaced points, and an equal number of bars of stock material are held in spindles which are rotatably mounted in a spindle head, which is intermittently rotated to index the bars successively into juxtaposition with each work station. The tools are mounted on a common tool slide which is designed to be advanced periodically to bring the tools into operative positions relative to the bars of stock, and the bars are constantly rotated about their respective axes by the spindles to cause the various tools carried by the tool slide to perform work on the bars. In Fig. 1 there is illustrated fragmentarily a rotatable spindle head l0 which carries a plurality of spindles II which terminate in chucks l2, only one of which is shown in the drawings, since all are identical in construction. The spindles II are positioned at spaced points within and around the periphery of the spindle head Ill and are designed to receive the several bars of stock M. The spindles H are rotated about their respective axes by suitable known driving means (not shown), the bars M being periodically advanced longitudinally of the spindles by suitable advancing means, which form a part of the known automatic machines and are not shown in the drawings for the sake of simplicity.

A knurling apparatus I5 is secured to a tool slide I6 which is intermittently actuated by means not shown, to cause it to move toward and away from the chuck I2. The knurling apparatus l5 comprises a standard or frame [9 secured to the tool slide it by means of a dovetail and slot connection 23 and a clamping plate 2| and screws 22 (Fig. 3). Secured in any suitable manner to the standard [9 within three spaced apertures 23 thereof, arranged on centers 120 apart and extending parallel to the tool slide it are sleeves 24 each having a similar cam groove 25 (Figs. 1, 3 and 4) in its peripheral wall. Reciprocably and rotatably mounted in each of the sleeves 24 is a knurling roll holder or shaft 21 from which extends radially a pin 28 which is entered in the cam groove 26. At their forward ends the shafts 21 are rotatably carried in a floating head member 29, the shafts each being prevented from moving longitudinally relative thereto by a collar 33 pinned to the shaft and entered in a recess formed in the head member and a retaining plate 33 secured to the head member and abutting the collars. The shafts 21 at their extreme forward ends are each formed with an eccentric portion 34 upon which is freely rotatably carried a knurling roll 35. A suitably recessed'and apertured plate 33 is secured to the forward end face of the head member 29 for receiving the rolls 35 and retaining them in longitudinal position upon the eccentric shaft portions 34 and at the same time permitting the necessary eccentric movements of the shaft portions 34 and the rolls movable therewith. Formed in the head member 29 and plate 33 are aligned recesses 3'1 for receiving the rotating bar stock 14 as the knurling apparatus I is advanced. It is to be understood that the shafts 21 and the cam grooves 26 as well as the rolls 35 carried on the eccentric shaft portions 34 are equally circumferentially spaced about the axis of the bar stock M. The rear ends of the shafts 21 are rotatably carried in aplate 40, the shafts each being prevented from moving longitudinally relative thereto by a collar 4| pinned to the shaft upon the forward side of the plate and a collar 42 threaded onto the shaft at the rear side of the plate.

Threaded into an enlargement on the rear side of the plate 49 is a rod 43 which extends a suitable distance therefrom and freely through an aperture in a stop lug 44 carried by a stationary part of the screw machine, the extreme end of the rod being threaded for the reception of a pair of adjustable stop collars 41. Surrounding each of the knurling roll shafts 21 between the standard l9 and the plate 33 of the head member 29 is a compression spring 48. The springs 48 jointly serve to normally advance the assembly comprising the shafts 21, head member 29 and plate 43 with the attached rod 43 relative to the standard [9 until the collars 4| abut the rear face of the standard l9, as shown in Fig. 1, wherein the apparatus is in its idle or retracted position relative to the bar stock l4 which is to be peripherally knurled. During the advance of the standard [3 with the tool slide It the shafts 21 and associated connected parts are caused to move therewith as a unit until the stop collars 41 abut the lug 44, as shown in broken outline in Fig. 1.

To permit the assembly comprising the head member 29, shafts 2! and knurling rolls 35 to slightly float within limits in case the bar stock I4 is slightly off-center relative to a center point about which the three rolls are radially arranged each of the shafts 21 is formed with a slight diametrical enlargement, indicated at 49, in Fig. 1, which extends a short distance along its length at each side of the pinZS. The enlargement 49 on the shaft 21 has a close sliding fit in the bore of the sleeve 23 while the diameter of the shaft at each side of the enlargement is such that it is slightly spaced from the peripheral surface of the sleeve bore. This arrangement permits such assembly to slightly adjust itself when the rolls 35 are simultaneously moved into engagement with the periphery of the bar stock in case an off-center condition, previously mentioned, exists.

In the operation of the screw machine equipped with the knurling apparatus l5, above described, one of the rotating bars of stock 14 is indexed at a predetermined period into juxtaposition with the left end of the knurling apparatus, as shown in Fig. l. The tool slide it carrying the standard l9 is thereafter advanced towards the left or forwardly through a predetermined distance. As the standard 19 moves forward, the head member 29, to which are attached for longitudinal movement the assembly including the shafts 21, is also moved forward until the stop collars 4'! upon the rod 43 carried by the plate 43 engage the stop lug 44 which arrests the further advance movement of the head member and shafts and therewith the knurling rolls 35. Atthis point in the movement of the tool slide IS the aligned knurling rolls 35 will have been moved to a position determined by the setting of the stop collars 41 on the rod 43 relative to the stop lug 44, thereby predeterminedly positioning the aligned knurling rolls 35 longitudinally of the bar stock M, as indicated by the broken outline of the rotating bar stock in Fig. 1. The knurling rolls 35 at this point in the operation of the apparatus are held in a retracted position out of the path of the bar stock I4 by the cooperative action of the cam grooves 2i: of the sleeves 24 and the pins 28 carried by the shafts 21, thus permitting the bar stock l4 to be freely entered therebetween in the forward movement of the head member 29.

In the continued advance movement of the tool slide I6 to complete its forward movement the standard 19 moving therewith advances the attached sleeves 24 having the cam grooves 26 and since the shafts 21 with the pins 28 are held stationary by the stop collars 41 abutting the stop lug 44 the grooves acting upon the pins cause simultaneous clockwise rotary movements (Figs. 2 and 3) to the shafts 21 (Figs. 2 and 3) and through the eccentric portions 34 thereof upon which the knurling rolls 35 are carried the latter are simultaneously rocked into operative engagement with the periphery of the rotating bar stock M which is consequently knurled, as indicated in broken outline at 50 (Fig. 1). The knurling rolls 35 are moved along an arcuate path which is relatively long before it engages the article and near dead center it moves into engagement therewith, thus producing the required leverage to provide a heavy pressure to form the knurl. Upon completion of the knurling operation, as just described, the tool slide I5 is moved backward to its normal position, whereupon the springs 43, which were progressively compressed during the forward movement of the tool slide, after the positioning of the rolls 35 longitudinally of the bar stock l4, expand and the head member 29 with its attached parts are moved relatively forward upon the standard l9, which is moving backward with the tool slide. The cam grooves 26 (Fig. 4) are so shaped that upon this relative forward movement of the head member 29 upon the standard I 9 taking place in the backward movement of the slide It the shafts 27 are rotated in a'co'unterclockwise direction (Figs. 2 and 3) to retract the knurling rolls 35 from operative engagement with the knurled periphery of the rotating bar stock I4. Upon the tool slide l reaching the limit of its backward movement the collars M on the shafts 21 will have abutted the right face of the standard I9, thereby correctly positioning the'head member 29 and the attached parts for the following cycle of operation of the knurling apparatus l5.

It will be apparent that the three equally spaced knurling roll holders 2! may be arranged at any convenient angle as a group about the axis of rotation of the bar stock I4. In the present arrangement (Figs. 2 and 3) the particular angle of the group of knurling roll holders 2! is due to the application of the knurling apparatus to a standard screw machine tool slide and this necessitated providing sufficient metal in the standard If! for receiving the clamping plate screws 22.

The point at which the length of bar stock [4 projecting from the chuck I2 is knurled, it will be understood, may be varied by adjusting the stop collars 41 relative to the stop lug 44. Also, that the depth of the knurl formed on the bar stock [4 may be varied by changing the position of the standard l9 upon the tool slide l6. Since the tool slide is in the operation of the machine is advanced a fixed distance and the bar stock I4 is longitudinally stationary the location of the standard l9 on the slide will determine the distance the pins 28 will move along the cam grooves 25, after the stop collars 4'! abut the lug 44 thereby controlling the extent of rotation of the shafts 2! and thus the distance the knurling rolls move toward and into knurling engagement with the bar stock I4. This last mentioned adjustment may also be used to provide for different diameters of bar stock within the capacity of the machine.

In the above described structure the knurling rolls 35 are carried upon the eccentric shaft portions 34 and the latter are equally spaced circumferentially about the axis of rotation of the bar stock l4 and thus the eccentric shaft portions are effective to simultaneously rock the rolls into operative engagement with the peripheral surface of the rotating bar stock. The arrangement is such that the required heavy pressure necessary to form the knurl to the desired depth upon the bar stock is accomplished without any deleterious lateral pressure or side strain being put on the rotating bar stock and consequently side strain upon the spindle II and its bearing (not shown) is reduced to a minimum and thus maintenance on the machine is likewise reduced.

Although the invention has been disclosed and described as embodied in a knurling apparatus, it is clear that it may have a more general application, for instance, for planishing operations, and that modifications can be made without departing from the spirit and scope of the appended claims.

What is claimed is:

1. In an article forming apparatus, a support, a plurality of spaced rotatable and reciprocable elements on said support arranged circumferentially about the axis of a rotating article, means for moving said elements as a unit to an advanced normal position on said support, article forming members eccentrically carried on said elements for simultaneous movement into engagement with the periphery of the article, means for advancing the support, the elements and forming members as a unit to predeterminedly position the latter longitudinally of the article, means effective for preventing further movement of the elements and forming members in the continued advance of the support, and means on said support cooperating with means on the rotatable elements effective after such positioning of the forming members for individually causing simultaneous rotary movements of the elements to move the members uniformly into forming engagement with the article.

2. In an article forming apparatus, a support, a plurality of rotatable and reciprocable shafts carried on said support equally spaced about the axis of a rotating article, means for causing said shafts to move as a unit to an advanced normal position on said support, means attached to ends of said shafts and abutting the support for limiting such movement, article forming rolls eccentrically carried on said elements at their opposite ends for simultaneous movement into engagement with the periphery of the article, means for advancing the support, the shafts and forming rolls as a unit to predeterminedly position the latter longitudinally of the article, an abutment, adjustable stop means reciprocable with said shafts and engageable with said abutment for preventing further movement of the shafts and rolls in the continued advance of the support, and means on said shafts engaged in cam grooves in said support effective after such positioning of the rolls for individually causing simultaneous rotary movements of the shafts to move the rolls uniformly into forming engagement with the article.

3. In an article forming apparatus, means for rotating an article, a support reciprocable longitudinally of the axis of rotation of the article, a plurality of elements rotatably and reciprocably mounted in said support and equally spaced about such axis of the article, means for moving said elements as a unit to an advanced normal position on said support, article forming members eccentrically carried on said elements for simultaneous movement into engagement with the periphery of the rotating article, means for mounting said elements and forming members on said support for limited bodily movement laterally of their axis of rotation, means for advancing the support, the elements and forming members as a unit to predeterminedly position the latter longitudinally of the article, means effective for preventing further movement of the elements and forming members in the continued advance of the support, and means on said support cooperating with means on the rotatable elements effective after such positioning of the forming members for causing simultaneous rotary movements of the elements to move the members into forming engagement with the article.

4. In an article knurling apparatus, means for rotating an article, a slide reciprocable longitudinally of the axis of rotation of the article, a plurality of shafts equally spaced circumferentially about and parallel to said axis of the article, said shafts being rotatably and reciprocably carried on said slide, means for connecting said shafts together for unitary reciprocation on said slide and effective to permit rotation of said shafts, resilient members for urging said connected shafts to an advanced normal position on said slide, means for limiting such movement, knurling rolls eccentrically and freely rotatably carried on said shafts and arranged for simultaneous moverotating article, means for advancing the slide, the shafts and rolls as a unit to predeterminedly position'the rolls longitudinally of the article, an abutment, means movable with the shafts engageable with said abutment for preventing further movement of the shafts and rolls in the continued advance of the slide, and means on the slide cooperating with means on the shafts after such positioning of the rolls for individually causing simultaneous rotary movements of the shafts to move the rolls uniformly into knurling engagement with the article.

5. In an article forming apparatus, means for rotating an article, a slide reciprocable longitudinally of the axis of rotation of the-article, a support secured to said slide and adjustable thereon in the direction of its reciprocation, a plurality of sleeves fixed to said support equally spaced circumferentially about said axis of the article, rotatable and reciprocable shafts carried in said sleeves, the shafts at opposite ends extending from said sleeves and support, said shafts at one end provided with eccentric portions, forming rolls freely rotatable on said eccentric portions and arranged for simultaneous movement into engagement with the periphery of the article, a head member surrounding said ends of the shafts and the rolls effective to connect said shafts together for unitary reciprocation on said support and to permit rotation thereof, res lient means surrounding the shafts and bearing upon opposite ends of said support and head member for urging said connected shafts to an advanced normal position on said slide, means for limiting such movement, means for advancing the slide, the shafts and rolls as a unit to predeterminedly position the rolls longitudinally of the article, the article being received in an aperture in the head member, means effective for preventing further movement of the shafts and rolls in the continued advance of the slide, and a pin extending from each of said shafts and engaged in cam grooves in said sleeves effective after such positioning of the rolls for individually causing simultaneous rotary movements of the shafts to move the rolls uniformly into forming engagement with the article.

JOHN S. STULL. 

